Our invention falls within the art of petalling small arms projectiles that are sometimes considered desirable for close range antipersonnel applications. We believe that initial delay of petalling relative to the rate of target penetration will increase the lethality of antipersonnel projectiles. Consequently, we have designed projectiles whose structure controllingly retards initial petalling rate.
Our improved projectile design includes an integral structure of an axial stem, a rear wall at the base of the stem and a jacket joined to the rear wall. A core surrounding the stem and partly encased by the jacket is made of softer material than the stem, rear wall and jacket. The jacket causes petalling retardation during initial stages of projectile impact wherein the core begins to break into elongate sectors. However, the rear wall is specially configured to enhance petalling motion of core sectors as a function of forward stem movement relative to these sectors, most of which movement occurs after the initial stages of projectile impact. Thus, at least some projectiles designed according to our disclosure will exhibit initial petalling retardation and subsequent petalling acceleration relative to projectile penetration rate. The cores of such projectiles will quickly widen or disperse after penetrating to relatively deeper, more vulnerable zones of the target, whereby projectile lethality is enhanced.